Is this right so far? Because in my textbook it says for i) x + y -1 = 0 instead of what I did. It also shows a few other different answers to what I did with some of my other questions.

Thanks!

Your answer to i) is the same answer, you've just swapped the signs (it is still correct but generally x should always be positive by convention). If you move everything over to the other side you will get what the book says.